Republican senators on Thursday morning warned President Trump that remaining in the landmark Paris climate pact will essentially guarantee that a host of Obama-era environmental regulations remain on the books for good.

In a letter to the president, the lawmakers urged Mr. Trump to withdraw from the deal, which calls on the U.S. to cut its greenhouse gas emissions by at least 26 percent by 2025. Mr. Trump, who vowed during his campaign to withdraw from the accord, has said he’ll make a decision after he returns home from the G-7 summit in Italy.

While some administration officials — including Secretary of State Rex W. Tillerson — want the U.S. to remain a part of the agreement, GOP senators argue that doing so could lead to the preservation of former President Barack Obama’s regulatory agenda, including the Clean Power Plan, the first set of national limits on carbon emissions from power plants.